JP3713217B2 - Inner pot for rice cooker - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an inner pot for a rice cooker employed in an induction heating rice cooker.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, various types of configurations for suppressing uneven cooking by promoting convection during rice cooking have been adopted in inner pots employed in induction heating rice cookers.
[0003]
For example, Japanese Patent Application Laid-Open No. 9-140570 and Japanese Patent Application Laid-Open No. 9-15564 disclose one having a plurality of irregularities formed on the bottom surface of the inner pot. Japanese Patent No. 3102363 discloses a dome-shaped curved protrusion at the center of the inner pot.
[0004]
[Problems to be solved by the invention]
However, in the former configuration having only a plurality of irregularities, even if partial convection is promoted on the inner surface of the inner pot, a heating state that is not so effective cannot be obtained as a whole. In addition, during induction heating, the heating at the convex portion is weakened, and it cannot be said that the structure is not necessarily an appropriate heating state.
[0005]
Moreover, in the latter structure which has a dome-shaped curved protrusion, there is a problem that it is difficult to scoop the cooked rice because of the protrusion. Moreover, since it is a protrusion of only the central part, the convection pattern is simple and insufficient to obtain a uniform heating state.
[0006]
Then, this invention makes it a subject to provide the inner pot for rice cookers provided with the structure which does not become obstructive also when scooping cooked rice while enabling uniform heating by induction heating.
[0007]
[Means for Solving the Problems]
As a means for solving the above-mentioned problems, the present invention provides an inner pot for a rice cooker that is formed in a bottomed cylindrical shape and is induction-heated by a coil disposed at two locations on the inner and outer circumferences below. Is a non-facing portion between a non-facing portion inside the facing position of the inner winding portion of the coil and a facing position of the inner winding portion of the coil and a facing position of the outer winding portion of the coil. In each of the portions, relief recesses are formed to suppress the influence of the lines of magnetic force generated when the coil is energized.
[0008]
With this configuration, it is possible to clarify the eddy current generation region, that is, the heat generation region in the bottom surface portion between the facing portion and the non-facing portion of the coil. Therefore, appropriate convection can be generated inside and uniform heating can be performed.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments according to the present invention will be described below with reference to the accompanying drawings.
[0011]
FIG. 1 shows an inner pot 1 for a rice cooker according to this embodiment. The inner pot 1 is induction-heated by a coil 3 attached to a protective frame 2 positioned below the inner pot 1. The coil 3 is wound in a state of being spaced apart at two locations on the inner and outer periphery. This is to change the heating state by separating the induction heating range of the inner pot 1 into two locations on the inner and outer circumferences facing the inner and outer winding parts 4a and 4b of the coil 3, respectively. This is to promote convection.
[0012]
By the way, the inner pot 1 has a configuration in which a plate-like body formed by joining and integrating a heat conductive layer and a heat generating layer with an intermediate metal layer such as copper is formed into a bottomed cylindrical shape by deep drawing. In this embodiment, it is formed in a cylindrical shape having a diameter of about 200 mm. The heat conductive layer is made of a material having high heat conductivity such as an aluminum alloy, and is located on the inner surface of the inner pot 1. The heat generating layer is made of a ferromagnetic material such as stainless steel and is located on the outer surface of the inner pot 1.
[0013]
At the time of deep drawing, the inner pot 1 is formed with relief recesses 5 and 6 at the center of the bottom surface and at two locations on the outer periphery thereof.
[0014]
As shown in FIG. 1 (b), the relief recess 5 is directed downward so as to be separated from the coil 3 from the position facing the inner circumferential winding portion 4 a of the coil 3 to the non-facing position on the inner side. It has curved surfaces 5a and 5b that are curved and then curved upward, and has a flat surface 5c on the inner side from the curved surface 5b. In other words, the curving surfaces 5a and 5b suppress the influence of the magnetic field, and the flat surface 5c ensures the scooping of the cooked rice inside the inner pot 1. In this embodiment, the radius of curvature of the curved surface 5a is about 15 mm, the radius of curvature of the curved surface 5b is about 16.5 mm, and the step between the curved surfaces 5a and 5b is about 2 mm.
[0015]
The escape recess 6 is annular, and has curved surfaces 6a, 6b, 6c formed so as to be separated from the coil 3, as shown in FIG. The escape recess 6 is formed in the opposite portion of the region between the inner peripheral winding portion 4 a and the outer peripheral winding portion 4 b of the coil 3. Since the escape recess 6 is located on the outer periphery of the bottom surface of the inner pot, the curved surfaces 6 a and 6 c ensure the ease of scooping the cooked rice, and the curved surfaces 6 a, 6 b and 6 c, mainly the curved surface 6 b are the coil 3. It acts so as to suppress the influence of the magnetic field from both the inner peripheral winding part 4a and the outer peripheral winding part 4b. In this embodiment, the curvature radii of the curved surfaces 6a and 6c are about 14 mm, the curvature radius of the curved surface 6b is about 17 mm, and the step between the curved surfaces 6a and 6c and the curved surface 6b is about 3.5 mm.
[0016]
Next, the heating state at the time of rice cooking by the inner pot 1 having the above-described configuration will be described.
[0017]
That is, when the coil 3 is energized, a magnetic field is generated around the coil 3 as shown by a loop arrow a in FIG. The influence of the magnetic field, that is, the strength of the magnetic field, rapidly decreases as the distance from the coil 3 increases. Accordingly, the inner pot 1 generates heat at the portion facing the coil 3, but the non-opposing portion slightly separated from the inner pan 1 is enlarged by the relief recesses 5 and 6 formed therein, so that the heat generation amount is greatly increased. Suppressed. For this reason, on the bottom surface of the inner pot 1, the amount of heat generation is greatly different between the facing portion and the non-facing portion of the coil 3. As a result, as shown by an arrow b in FIG. 1, in the inner pot 1, the upward flow along the inner surface on the outer peripheral side, and the arc shape between the escape recesses 5 and 6 on the inner peripheral side. Are generated, and a good convection state is obtained. Therefore, uniform and uniform heating becomes possible, and cooked rice can be cooked deliciously.
[0018]
In addition, in the said embodiment, although escaped recessed parts 5 and 6 were formed only in two places of the bottom face center part of the inner pot 1, and its outer peripheral part, Furthermore, an outer peripheral part, ie, the outer peripheral side winding part of the coil 3 Further, it may be formed at a portion (indicated by A in FIG. 1) facing the outer peripheral region of 4b.
[0019]
【The invention's effect】
As is apparent from the above description, according to the present invention, since the relief recess that suppresses the influence of the lines of magnetic force generated when the coil is energized is formed in the non-opposing portion of the coil, the heat generation region is formed in the opposing region of the coil. It is possible to concentrate and obtain a good cooked rice state.
[Brief description of the drawings]
1A is an overall cross-sectional view of an inner pot for a rice cooker and a coil according to the present embodiment, and FIGS. 1B and 1C are enlarged cross-sectional views of escape recesses thereof.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Inner pan 2 ... Protective frame 3 ... Coil 4a, 4b ... Inner peripheral side winding part, outer peripheral side winding part 5, 6 ... Escape recessed part 5a, 5c, 6a, 6b, 6c ... Curved surface 5b ... Flat surface

Claims (1)

In an inner pot for a rice cooker that is formed in a bottomed cylindrical shape and is induction-heated by a coil disposed in two locations on the inner and outer circumferences below it,
At least on the bottom surface portion, a non-opposing portion inside the opposed position of the inner circumferential winding portion of the coil, an opposed position of the inner circumferential winding portion of the coil, and an opposed position of the outer circumferential winding portion An inner pot for a rice cooker, in which relief recesses are formed in the non-opposing portion between the two to suppress the influence of magnetic lines of force generated by energization of the coil.

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